Re: [PATCH 25/30] nios2/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT
From: Dinh Nguyen
Date: Fri Feb 25 2022 - 09:29:45 EST
On 2/25/22 02:52, Anshuman Khandual wrote:
On 2/25/22 7:01 AM, Dinh Nguyen wrote:
Hi Anshuman,
On 2/13/22 20:30, Anshuman Khandual wrote:
This defines and exports a platform specific custom vm_get_page_prot() via
subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX
macros can be dropped which are no longer needed.
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Acked-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
---
arch/nios2/Kconfig | 1 +
arch/nios2/include/asm/pgtable.h | 16 ------------
arch/nios2/mm/init.c | 45 ++++++++++++++++++++++++++++++++
3 files changed, 46 insertions(+), 16 deletions(-)
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index 33fd06f5fa41..85a58a357a3b 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -6,6 +6,7 @@ config NIOS2
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_HAS_DMA_SET_UNCACHED
+ select ARCH_HAS_VM_GET_PAGE_PROT
select ARCH_NO_SWAP
select COMMON_CLK
select TIMER_OF
diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
index 4a995fa628ee..2678dad58a63 100644
--- a/arch/nios2/include/asm/pgtable.h
+++ b/arch/nios2/include/asm/pgtable.h
@@ -40,24 +40,8 @@ struct mm_struct;
*/
/* Remove W bit on private pages for COW support */
-#define __P000 MKP(0, 0, 0)
-#define __P001 MKP(0, 0, 1)
-#define __P010 MKP(0, 0, 0) /* COW */
-#define __P011 MKP(0, 0, 1) /* COW */
-#define __P100 MKP(1, 0, 0)
-#define __P101 MKP(1, 0, 1)
-#define __P110 MKP(1, 0, 0) /* COW */
-#define __P111 MKP(1, 0, 1) /* COW */
/* Shared pages can have exact HW mapping */
-#define __S000 MKP(0, 0, 0)
-#define __S001 MKP(0, 0, 1)
-#define __S010 MKP(0, 1, 0)
-#define __S011 MKP(0, 1, 1)
-#define __S100 MKP(1, 0, 0)
-#define __S101 MKP(1, 0, 1)
-#define __S110 MKP(1, 1, 0)
-#define __S111 MKP(1, 1, 1)
/* Used all over the kernel */
#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
diff --git a/arch/nios2/mm/init.c b/arch/nios2/mm/init.c
index 613fcaa5988a..311b2146a248 100644
--- a/arch/nios2/mm/init.c
+++ b/arch/nios2/mm/init.c
@@ -124,3 +124,48 @@ const char *arch_vma_name(struct vm_area_struct *vma)
{
return (vma->vm_start == KUSER_BASE) ? "[kuser]" : NULL;
}
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) {
+ case VM_NONE:
+ return MKP(0, 0, 0);
+ case VM_READ:
+ return MKP(0, 0, 1);
+ /* COW */
+ case VM_WRITE:
+ return MKP(0, 0, 0);
+ /* COW */
+ case VM_WRITE | VM_READ:
+ return MKP(0, 0, 1);
+ case VM_EXEC:
+ return MKP(1, 0, 0);
+ case VM_EXEC | VM_READ:
+ return MKP(1, 0, 1);
+ /* COW */
+ case VM_EXEC | VM_WRITE:
+ return MKP(1, 0, 0);
+ /* COW */
+ case VM_EXEC | VM_WRITE | VM_READ:
+ return MKP(1, 0, 1);
+ case VM_SHARED:
+ return MKP(0, 0, 0);
+ case VM_SHARED | VM_READ:
+ return MKP(0, 0, 1);
+ case VM_SHARED | VM_WRITE:
+ return MKP(0, 1, 0);
+ case VM_SHARED | VM_WRITE | VM_READ:
+ return MKP(0, 1, 1);
+ case VM_SHARED | VM_EXEC:
+ return MKP(1, 0, 0);
+ case VM_SHARED | VM_EXEC | VM_READ:
+ return MKP(1, 0, 1);
+ case VM_SHARED | VM_EXEC | VM_WRITE:
+ return MKP(1, 1, 0);
+ case VM_SHARED | VM_EXEC | VM_WRITE | VM_READ:
+ return MKP(1, 1, 1);
+ default:
+ BUILD_BUG();
+ }
+}
+EXPORT_SYMBOL(vm_get_page_prot);
I'm getting this compile error after applying this patch when build NIOS2:
Hmm, that is strange.
Did you apply the entire series or atleast upto the nios2 patch ? Generic
vm_get_page_prot() should not be called (which is build complaining here)
when ARCH_HAS_VM_GET_PAGE_PROT is already enabled on nios2 platform.
Ran a quick build test on nios2 for the entire series and also just upto
this particular patch, build was successful.
Ok, I did not apply the whole series, just this patch.
Dinh